The invention described herein is a fixed lens for use with a new type of variable focus spectacles for presbyopes.
As people age, they gradually lose the ability to focus their eyes at various distances. After about the age of 40, the loss of “accommodation” (as the adjustable focusing ability of humans is called) generally becomes so severe that for almost all people it is not possible to focus both on distant objects and on objects at reading distance, even after distance vision has been corrected. Special types of spectacles have been developed to address this problem: bifocals, trifocals and “PALs” (Progressive Addition Lens). But these types of spectacles have serious deficiencies. They require the user to look through different regions of the lens when trying to focus on objects at different distances from the user. For example, a PAL user must look through the upper portion of the lens when looking at a distant object, and through a very small region in the lower center of the lens when reading a book. Similarly, bifocal users also must look through a small region in the lower portion of the lens to read. Such restrictions are unsatisfactory in many circumstances.